During production of warp knitted jacquard fabrics, jacquard pattern designs are achieved by means of thick and thin fabric textures, and the amounts of yarns used by thick and thin fabric textures differ considerably, thus resulting in uneven warp tension in different areas during weaving process. A jacquard warp tensioning device of a presently used warp knitting machine comprises a pair of parallel side panels disposed on two sides of the machine casing, a warp beam, a plurality of warp guide rods and a flat spring warp dividing device—all disposed between the pair of side panels, the warp beam being positioned at the upper portions of the two side panels, the plurality of warp guide rods and the flat spring warp dividing device being disposed successively at positions lower than that of the warp beam, the flat spring warp dividing device comprising a plurality of flat springs. Yarns are fed to the warp knitting machine by the warp beam and the warp beam is wound up with a large number of parallelly arranged warp yarns, and after being conveyed from the warp beam, the warp yarns first revolve round the plurality of warp guide rods and then pass through the flat spring warp dividing device, so that the warp yarns move longitudinally forward in a Z-shape. When the designed pattern is large, the warp tensions at the areas where thick textures are woven tend to be too high, the flat springs bend downwards to prevent tension excessiveness, and the warp tensions at the areas where thin textures are woven tend to be too low, the flat springs upwardly spring back to prevent tension inadequacy. However, since the extent of bending and the extent of springback are limited, tension compensation level is low and this results in an increased yarn breakage ratio and a low weaving efficiency. In addition, surfaces of the farbrics produced are uneven due to tension imbalance.